Fitness rings · Model guide · Maker specs
Oura Ring 4
Get Oura Ring 4 if you need a size Ring 5 doesn't make: Ring 4 comes in 4 to 15, Ring 5 in 6 to 13 only.
Product images
Oura Ring 4, from its Amazon listing.
Credit: Amazon.com (Associates Program). Amazon listing
Product image from the Amazon listing.
In short
Get Oura Ring 4 if you need a size Ring 5 doesn't make: Ring 4 comes in 4 to 15, Ring 5 in 6 to 13 only. It's the bigger ring, 7.9mm wide and about 2.88mm thick, with typically 5–8 days of battery, and it stores up to a week of data between syncs. Like Ring 5, most of the app needs a paid Oura Membership at $5.99 a month.
Who it is for
- People who wear a size 4, 5, 14 or 15. Ring 5 only comes in 6–13, so Ring 4 is the Oura that fits.
- Anyone who goes days without opening the app. Ring 4 stores up to seven days of data, against three on Ring 5.
- Anyone who'd rather have flatter sensors against the skin. Ring 4's are recessed, with a 0.3mm dome, where Ring 5's dome stands 0.7mm.
Who should skip it
- Anyone who fits sizes 6–13 and wants the smallest Oura. Ring 5 is 6.09mm wide and 2.28mm thick, against 7.9mm and about 2.88mm for Ring 4.
- Anyone who won't keep paying for the membership after the free first month, or who wants 10–14 days between charges. Ring 4 needs Oura Membership for most features and is rated for 5–8 days.
What sets it apart
- The widest size range Oura sells, 4 to 15, sized with its own Ring 4 kit.
- Recessed sensors and Smart Sensing, which Oura says adapts to your finger's structure, your skin tone and your activity while it manages battery.
- Typically 5–8 days per charge, and 20–80 minutes to recharge, depending on how low it is.
- From $349 in Silver or Stealth at Oura's US store on 19 September 2026.
Caveats
- Oura says finishes and sizes depend on its current inventory, so the one you want may sell out; on 19 September 2026 the US store still listed Gold, Silver and Stealth.
- It's a wellness ring, not a medical device, by Oura's own description.
Key specs
In the same order on every ring page, so you can compare models.
| Spec | Value | Source and notes |
|---|---|---|
| Materials | Titanium inside and out, with a PVD or DLC coating depending on the finish; non-allergenic, BPA-free titanium inner shell | Oura Ring 4 support |
| Width | 7.9 mm | Oura Ring 4 support |
| Thickness | About 2.88 mm; recessed sensor dome 0.3 mm | Oura Ring 4 support |
| Weight | 3.3–5.2 g, depending on size (titanium model) | Oura Ring 4 support |
| Sizes | 4–15 (Ring 4 sizing kit) | Oura Ring 4 support |
| Finishes | Gold, Silver, Stealth (Oura US store, 19 September 2026) | Oura storeOura says finishes and sizes depend on current inventory. |
| Battery | Typically 5–8 days | Oura Ring 4 supportVaries with ring size, settings, activity and battery age. |
| Charging | Typically 20–80 minutes, depending on the starting charge | Oura Ring 4 support |
| Charging case | Size-specific charging dock and USB cable in the box; not a travel case like Ring 5's | Oura General FAQs (updated 18 September 2026); Use Your Oura Ring Charger |
| Water resistance | 100 m (328 ft). Ring 4 support: sauna and water sports, not diving. General FAQs and Product Safety: showering, swimming, recreational diving and snorkeling are fine; no scuba; don't leave it submerged for more than 12 hours | Oura Ring 4 support; General FAQs (updated 18 September 2026); Product Safety & Use |
| Sensors | Smart Sensing; 3 photodetectors and 2 triple LEDs (red, green, infrared); digital temperature sensor; accelerometer | Oura Ring 4 support |
| Sleep tracking | Detailed sleep analysis with membership; nighttime blood oxygen (SpO2) from the red and infrared LEDs | Oura Ring 4 support |
| Activity / fitness | 24/7 heart rate; Automatic Activity Detection; dynamic activity goals (membership) | Oura Ring 4 support |
| App | Oura app | Oura Ring 4 support |
| Subscription / data access | Oura Membership (US $5.99/month or $69.99/year; 1 free month for new members). Same account-based membership as Ring 5 | Oura Membership support (updated 8 September 2026); Oura Ring 4 support |
| Phone platforms | iOS 16 or later, or Android 11 or later with Google Play; the phone must support Bluetooth 5.0 | Oura General FAQs; Set up the Oura App |
| Wireless | Bluetooth Low Energy (Bluetooth Smart); Airplane Mode; EMF-safe; FCC certified | Oura Ring 4 support |
| On-ring storage | Up to one week (seven days) | Oura Ring 5 support (Ring 4 column of its comparison table) |
| US price | From $349 (Silver, Stealth) on 19 September 2026 | Oura store |
| Price band | Previous-generation flagship, plus the membership | Oura store |
| Announced | 2024 | Oura Ring 4 support (updated 18 June 2026) |
| Availability | On sale at Oura's US store on 19 September 2026; Oura says to check its store or an authorized retailer for stock | Oura Ring 4 support; Oura store |
Oura Ring 4 extras
Specs only this model has.
| Spec | Value | Source and notes |
|---|---|---|
| Smart Sensing | Oura's sensing system: the algorithm adapts to your finger's structure, skin tone and activity while managing battery, Oura says | Oura Ring 4 support |
| Ring 4 Ceramic | Zirconia ceramic outside, same sensors; 7.9 × 3.51 mm; 5.1–8.1 g | Oura Ring 4 support |
| Sizing kit | Ring 4 kit: white sizers, 4–15. Not the Ring 5 kit (6–13) | Oura Ring 4 support |
| Operating temperature | Ring 4 support: −10 to 54 °C (14 to 129 °F). General FAQs and Product Safety: −10 to 52 °C (14 to 125 °F). Charge at room temperature | Oura Ring 4 support; General FAQs; Product Safety & UseOura's pages give two different upper limits. |
| Latest firmware | 2.12.0 (17 June 2026): internal optimizations and bug fixes. No newer Ring 4 build as of 19 September 2026 | Oura Device Firmware Versions (updated 17 June 2026) |
Where Ring 4 sits next to Ring 5
Ring 4 is Oura’s 2024 ring, and Oura still sells it beside the newer, smaller Ring 5. The two share an app and a membership, so the choice comes down to fit, size range and how often you sync.
| Spec | Oura Ring 4 | Oura Ring 5 |
|---|---|---|
| Sizes | 4–15 | 6–13 |
| Width and thickness | 7.9 × about 2.88 mm | 6.09 × 2.28 mm |
| Sensor dome | 0.3 mm, recessed | 0.7 mm |
| Data stored on the ring | Up to 7 days | Up to 3 days |
| Sizing kit | Ring 4 kit, white sizers | Ring 5 kit, sized slightly differently |
| App and membership | Same | Same |
If you wear a 6 to 13 and want less ring on your finger, Ring 5 is the one. Ring 4 is the pick at either end of the size range, and for anyone who’d rather not open the app every few days. The full head-to-head is in Oura Ring 4 vs Oura Ring 5.
Titanium or ceramic
Ring 4 also comes as Oura Ring 4 Ceramic, with the same Smart Sensing in a zirconia ceramic shell. Ceramic weighs 5.1–8.1 grams and is 3.51mm thick, against 3.3–5.2 grams and about 2.88mm for titanium. Both are 7.9mm wide and come in sizes 4–15.
Battery and charging
Oura rates Ring 4 at typically 5–8 days, depending on ring size, settings, activity and battery age. Recharging takes 20–80 minutes, depending on how low it is, on a dock made for your ring size; the dock and a USB cable come in the box. That’s a dock, not the travel case Ring 5 has.
Sensors, sleep and the app
Ring 4 uses two triple LEDs (red, green and infrared), three photodetectors, a digital temperature sensor and an accelerometer. Oura’s Smart Sensing adjusts how it reads them to your finger, skin tone and activity, and the red and infrared LEDs measure blood oxygen at night.
Oura Membership unlocks the same features on Ring 4 as on Ring 5, from detailed sleep analysis and 24/7 heart rate to Stress, Heart Health and Women’s Health, plus automatic activity detection and activity goals that adjust to you. The Oura app runs on iOS 16 or later and on Android 11 or later with Google Play, on a phone with Bluetooth 5.0. Ring 4’s latest firmware was 2.12.0, a bug-fix release from 17 June 2026.
Price
Ring 4 started at $349 in Silver and Stealth on Oura’s US store on 19 September 2026, with Gold at $399–$499. When the store switched to euros that day, it showed Ring 4 from €265.30. Membership adds $69.99 a year, or $5.99 a month, once the free month ends. Stock varies, so check before you buy.
Sources
- Amazon product listing — accessed 2026-09-20
- Oura Member Care — Oura Ring 4 (updated 18 June 2026) — accessed 2026-09-19
- Oura store — accessed 2026-09-19
- Oura Member Care — Discover Oura Ring 5 (Ring 4 comparison) — accessed 2026-09-19
- Oura Member Care — Oura Membership — accessed 2026-09-19
- Oura Member Care — General FAQs — accessed 2026-09-19
- Oura Member Care — Product Safety & Use — accessed 2026-09-19
- Oura Member Care — Device Firmware Versions — accessed 2026-09-19
Frequently asked questions
Is Oura Ring 4 discontinued?
No. Oura's US store still sold it on 19 September 2026, alongside Ring 4 Ceramic; Ring 5 is the newer model.
Does Ring 4 need Oura Membership?
Yes, for most of the app. It uses the same account-based membership as Ring 5, which in the US costs $69.99 a year or $5.99 a month after a free first month for new members. Oura says Gen2 is the generation that doesn't require it.
Can I use a Ring 5 sizing kit?
No. Oura makes a kit for each generation. Ring 4's white sizers cover 4–15; the Ring 5 kit covers 6–13, and by Oura's account Ring 5 sizes slightly differently.
Can I swim or dive with Ring 4?
Swimming, yes: it's rated to 100 meters (328 feet). Diving is less clear. Oura's Ring 4 page says sauna and water sports but not diving, while its general FAQ allows recreational diving and snorkeling. Neither allows scuba, and the FAQ caps time underwater at 12 hours.
Official product page: Oura Ring 4. Specs: Oura Ring 4 specs.